E.g.f.: exp(exp(sinh(x))-1)-1.

Terms

a(0) =0a(1) =1a(2) =2a(3) =6a(4) =23a(5) =103a(6) =535a(7) =3153a(8) =20676a(9) =149148a(10) =1172343a(11) =9960085a(12) =90864801a(13) =885278605a(14) =9167936406a(15) =100508961982